Gene Therapy Clinical Trials 2026 — AAV, CRISPR, and Lentiviral Pipeline Tracker

Why gene therapy trial monitoring matters in 2026

Gene therapy has moved from theoretical to commercial faster than almost any prior technology in medicine. The FDA approved five new gene therapy products in a 24-month window from 2022–2023 alone: Hemgenix (hemophilia B), Roctavian (hemophilia A, later withdrawn), Casgevy and Lyfgenia (sickle cell disease), and Elevidys (Duchenne muscular dystrophy). The field is now in a commercial validation phase — early approvals are establishing real-world evidence while next-generation programs compete on durability, safety, and scalability.

The 2026 gene therapy pipeline spans four delivery modalities and a dozen rare disease indications. Each Phase 3 readout reshapes competitive dynamics for the programs behind it. BD teams, investors, and clinical researchers monitoring this space need to track not just their own programs but the full competitive context — who is recruiting, who is enrolling, and what endpoint changes signal a study in trouble or ahead of schedule.

Gene therapy delivery modalities — 2026 pipeline overview

AAV (Adeno-Associated Virus) — the dominant platform

AAV gene therapy accounts for the majority of approved products and late-stage pipeline in 2026. AAV's tissue tropism (different serotypes target liver, muscle, eye, CNS), established manufacturing track record, and non-integrating profile make it the default choice for single-gene deficiency disorders. Active Phase 3 AAV programs include:

• Hemophilia B: CSL Behring's etranacogene dezaparvovec (Hemgenix, NCT06003387) — actively recruiting for additional safety/effectiveness data post-approval. Janssen's AAV5-hRKp.RPGR follow-up study
• Hemophilia A: Pfizer's giroctocogene fitelparvovec (NCT03861273) is active-not-recruiting (enrollment complete). Shanghai Xinzhi BioMed hemophilia A program recruiting
• Retinal dystrophies: AbbVie/REGENXBIO's RGX-314 (NCT04704921) — subretinal AAV8 delivery of anti-VEGF gene for wet AMD. Ocugen's OCU400 (NCT06388200) for NR2E3-associated retinal dystrophies including retinitis pigmentosa. Janssen AAV5-RPGR for X-linked retinitis pigmentosa (Japan, NCT05926583)
• Duchenne muscular dystrophy: Sarepta Therapeutics' SRP-9003 (NCT06246513) Phase 3 for non-ambulatory patients. Solid Biosciences' SGT-003 (NCT07160634) — recruiting ambulatory males
• Neurological/metabolic: Ultragenyx's DTX301 AAV for OTC deficiency (NCT05345171) enrollment complete. Neurogene's NGN-401 regulated gene therapy for Rett syndrome (NCT05898620) — recruiting females with MECP2 mutations
• Rett syndrome: Taysha Gene Therapies' TSHA-102 miniMECP2 (NCT05606614, NCT07480564) — two Phase 3 studies for females and adult patients

CRISPR/Base Editing — the precision approach

CRISPR-based gene therapy reached a commercial inflection point in December 2023 with FDA approval of Casgevy (exa-cel, Vertex/CRISPR Therapeutics) — the first approved CRISPR medicine. Casgevy edits BCL11A enhancer in patient-derived stem cells to reactivate fetal hemoglobin (HbF), effectively curing or significantly reducing sickling in SCD and transfusion-dependent beta-thalassemia. Follow-on Phase 3 studies (NCT05356195, NCT05329649, NCT05477563) are expanding the approved indication to pediatric patients.

Base editing represents the next generation: Beam Therapeutics' BEAM-101 uses adenine base editing to introduce an HbF-inducing edit without generating double-strand DNA breaks. Early Phase 1/2 data show durable HbF reactivation with a conditioning-dose-dependent response. The base editing approach may offer a wider therapeutic window and lower off-target risk than nuclease-based CRISPR, though durability data are still accumulating.

Lentiviral gene therapy

Lentiviral vectors integrate into the genome, providing permanent transgene expression. bluebird bio pioneered this approach for hemoglobinopathies — betibeglogene (Lyfgenia, for SCD) and beti-cel (Zynteglo, for TDT) are both approved. The field has shifted somewhat toward CRISPR after early safety concerns over insertional mutagenesis, but lentiviral programs continue for hematologic malignancies and certain CNS indications where genomic integration is necessary for long-term expression.

Phase 3 gene therapy pipeline — 2026

As of March 2026, 19 gene therapy trials (AAV, lentiviral, CRISPR — excluding CAR-T) are in Phase 3 and actively enrolling, recently enrolled, or approaching completion:

NCT ID	Sponsor	Program / Indication	Status
NCT06003387	CSL Behring	Etranacogene dezaparvovec (Hemgenix) — Hemophilia B	Recruiting
NCT04704921	AbbVie / REGENXBIO	RGX-314 — Wet AMD (subretinal AAV8)	Recruiting
NCT07160634	Solid Biosciences	SGT-003 — Duchenne Muscular Dystrophy	Recruiting
NCT05898620	Neurogene	NGN-401 (regulated MECP2) — Rett Syndrome	Recruiting
NCT05606614	Taysha Gene Therapies	TSHA-102 miniMECP2 — Rett Syndrome (females)	Recruiting
NCT06111638	Shanghai Xinzhi BioMed	AAV-F8 — Hemophilia A	Recruiting
NCT05477563	Vertex / CRISPR Therapeutics	CTX001 (exa-cel / Casgevy) — SCD (adults)	Recruiting
NCT03861273	Pfizer	Giroctocogene fitelparvovec — Hemophilia A	Enrolled
NCT06246513	Sarepta Therapeutics	SRP-9003 — Duchenne Muscular Dystrophy	Enrolled
NCT05356195	Vertex / CRISPR Therapeutics	CTX001 (exa-cel / Casgevy) — SCD (pediatric)	Enrolled
NCT05329649	Vertex / CRISPR Therapeutics	CTX001 (exa-cel / Casgevy) — SCD (pediatric, intl)	Enrolled
NCT06388200	Ocugen	OCU400 — NR2E3 Retinitis Pigmentosa	Enrolled
NCT04794101	Janssen	AAV5-RPGR — X-linked Retinitis Pigmentosa (follow-up)	Enrolled
NCT05345171	Ultragenyx	DTX301 — OTC Deficiency (ornithine transcarbamylase)	Enrolled

Gene therapy by indication — active trial landscape

Hemophilia (A and B) — most commercially advanced

Hemophilia is the most mature indication for AAV gene therapy. Hemgenix (etranacogene dezaparvovec, CSL Behring) for hemophilia B received FDA approval in 2022 at $3.5M — the most expensive therapy ever approved at the time. Pfizer's giroctocogene fitelparvovec (fidanacogene elarvovec-rokf) for hemophilia A completed Phase 3 enrollment and is awaiting readout. Both programs replace the deficient clotting factor (Factor IX or Factor VIII) using hepatotropic AAV serotypes that drive liver-targeted expression.

The key clinical question is durability: early gene therapy studies showed factor levels declining over time due to immune-mediated transduction loss and capsid-directed T cell responses. How sponsors manage this — through immunosuppression protocols, redosing strategies, or improved capsid engineering — will define competitive differentiation in 2026.

Duchenne Muscular Dystrophy — compressed timeline

DMD gene therapy operates under significant time pressure: the therapeutic window is patients who are still ambulatory. Sarepta's Elevidys (delandistrogene moxeparvovec) received accelerated FDA approval in June 2023 for ages 4–5. The Phase 3 EMBARK trial for 4–7 year olds missed its primary endpoint (Motor Function Measure) — Sarepta is pursuing full approval via a different path. Solid Biosciences' SGT-003 delivers a novel shortened dystrophin construct (SRP-9003) that spans a different region of the dystrophin protein and is now in Phase 3 recruiting ambulatory males. Watch for the EMBARK confirmatory data decision and Solid's recruiting velocity as competing signals in 2026.

Retinal gene therapy — first wave and next generation

Luxturna (voretigene neparvovec, Spark Therapeutics/Roche) was the first AAV gene therapy approved in the US (2017) for RPE65-associated retinal dystrophy. The second wave is now in Phase 3:

• AbbVie/REGENXBIO RGX-314 — subretinal delivery of AAV8 expressing anti-VEGF nanobody for wet AMD. Phase 3 Pivotal 1 study is actively recruiting. If successful, would eliminate the need for repeated anti-VEGF injections (currently Eylea/Lucentis ~$2K/injection, 6–12x/year)
• Ocugen OCU400 — broad-spectrum retinal gene therapy using the nuclear hormone receptor NR2E3 to potentially treat multiple forms of retinitis pigmentosa from different mutations. Enrollment recently completed
• Janssen AAV5-RPGR — targeting RPGR mutations in X-linked retinitis pigmentosa, running a Phase 3 in Japan

Neurological disorders — Rett syndrome becomes a hot field

Rett syndrome, a severe X-linked neurodevelopmental disorder caused by MECP2 mutations, has drawn an unusual level of Phase 3 competition in 2026 with two programs enrolling simultaneously:

• Neurogene NGN-401 — a regulated (self-complementary) MECP2 gene therapy specifically designed to address MECP2 dosage sensitivity. Full gene expression would be toxic, so NGN-401 incorporates a microRNA-based regulatory circuit. Phase 1/2/3 study recruiting females with Rett
• Taysha TSHA-102 — uses a miniaturized MECP2 construct (miniMECP2) delivered via AAV9. Two Phase 3 studies: one for symptomatic females aged 2+, one for females with advanced disease

The Rett field illustrates a key dynamic in gene therapy: when two programs for the same rare disease reach Phase 3 simultaneously, competitive intelligence on enrollment pace and safety signals becomes critically important for investors and BD teams following either program.

Sickle cell disease — from approval to next-generation access

SCD gene therapy reached commercial approval in December 2023 (Casgevy and Lyfgenia). The challenge now is access: the ~$2.2–3.1M price per patient, 20+ hospital sites authorized to administer these therapies, and 4–6 month manufacturing lead time limit real-world uptake. The Phase 3 expansion trials for pediatric patients (Vertex/CRISPR Therapeutics) are part of Vertex's effort to broaden the labeled population. In parallel, in vivo gene editing approaches (Beam Therapeutics BEAM-101 in Phase 1/2) are pursuing a path that could scale more easily.

Who uses gene therapy clinical trial monitoring

• Rare disease BD teams — tracking competing gene therapy programs across AAV, CRISPR, and lentiviral approaches for in-licensing decisions and competitive benchmarking
• Healthcare investors — monitoring Phase 3 initiation, enrollment pace, and protocol amendments as leading indicators of trial trajectory
• CROs and clinical operations teams — tracking competitive site footprints for rare disease indications with small patient populations
• Gene therapy developers — monitoring regulatory strategy shifts and endpoint choices by competing programs
• Patient advocacy organizations — tracking available trial options for patients with rare genetic diseases

What we monitor for gene therapy trials

Our system pulls from the ClinicalTrials.gov API every day. For a gene therapy watch profile, you can configure alerts for:

• Modality keywords: "AAV", "adeno-associated virus", "gene therapy", "lentiviral", "CRISPR", "base editing", "gene editing", "viral vector"
• Target keywords: "MECP2", "dystrophin", "Factor VIII", "Factor IX", "BCL11A", "RPE65", "RPGR" — or any gene target you're following
• Sponsor tracking: Vertex, Sarepta, Pfizer, AbbVie, CSL Behring, Solid Biosciences, Taysha, Neurogene, Ultragenyx, bluebird bio
• Phase and status filters: Phase 3 only, or Phase 1/2 if tracking early pipeline
• Status changes: New registrations, enrollment opens, protocol amendments, and results postings

Related clinical trial trackers

• CAR-T Cell Therapy Clinical Trials — 245 active trials, 6 in Phase 3. Oncology and autoimmune CAR-T programs.
• Sickle Cell Disease Clinical Trials — Gene therapy, gene editing, and small molecule programs for SCD.
• Duchenne Muscular Dystrophy Clinical Trials — Exon skipping, gene therapy, and utrophin upregulation programs.
• Hemophilia Clinical Trials — AAV gene therapy, gene editing, and factor replacement for hemophilia A and B.
• Multiple Myeloma Clinical Trials — CAR-T, bispecific antibodies, and novel myeloma approaches.

Pricing

Free: 1 disease/keyword profile, daily change tracking, ClinicalTrials.gov monitoring. No credit card required.

Starter — $29/month: 5 disease/keyword profiles, daily digest, phase and sponsor filters.

Pro — $99/month: Unlimited profiles, priority email delivery, CSV export. Best for BD teams and investors.